Postcrossing - Postcards from around the World

I was introduced to Postcrossing by a good friend of mine. Postcrossing is an interesting group activity / project, and the goal is to:

allow people to receive postcards from all over the world, for free. Well, almost free! The main idea is that: if you send a postcard, you'll receive at least one back, from a random Postcrosser from somewhere in the world.
Why? Because, like the author, there are lots of people who like to receive real mail. The element of surprise of receiving postcards from different places in the world (many of which you'd probably never have heard of) can turn your mailbox into a box of surprises - and who wouldn't like that?

I registered but didn't really send any postcards (oops!). Eventually my account got deleted due to inactivity. My friend did participate and he has sent (and received) quite a number of the postcards from around the world. It is a novel idea, and brings the world together, effectively making it smaller.

There are a significant number of users from Singapore, 568 users who have sent 7711 postcards to be exact (as of now). For a country that barely sent out any number of personal letters / postcards, having such Postcrossing figures is quite impressive. :)

An additional interesting feature is the showcasing of the different postcards sent and received, such that through this website, one could almost see the different postcards from around the world! Here's the page from Singapore (again), where the postcards and the users are shown.